Today, denim products have been much popular as pants, trousers and/or jackets. These denim products are made of thick cotton fabrics whose warps are dark blue and whose wefts are white and which are of diagonal weave or plain weave. There are generally two methods for producing design patterns on these denim products, one of which is a chemical washing method in which said denim products are put into a drum cage and a specified quantity of pumice which has been immersed and seasoned in an aqueous solution of calcium hypochlorite is put in said drum cage altogether and marble-like spotted design patterns can be produced by aid of rubbing and friction between said denim woven products and said pumice by rotating said denim woven products together said pumice in said rotary drum cage, and the other of which is called a chemical bleaching method in which said denim woven products are agitated for a specified period of time in an aqueous solution of calcium hypochlorite having a concentration of about 6%, thereby causing said denim woven products to be totally white-bleached.
In the former chemical washing method, the design is produced by only a number of irregular spots, and in the latter chemical bleaching method said denim woven products are only totally white-bleached. Namely in either case, produced design is merely vague. Therefore, these two conventional methods do not meet any requirements of recent youngsters who want that design pattern is novel, bold and individual and do not give us any designs of free drawing or painting.